Back again..!... The GT6041 powered "Green Beast"..!

[Deleted]

Hi..... if you are teed off the afterburner fuel, and the pressure in the c/c is higher than that in the a/b there is a good chance the fuel will follow the path of least resistance ? you could floor the throttle just as you put the hot streak on, we have done this in the past to light if afterburner ignition fails. put a check in line on the a/b side of the tee set at 5 psi.... may work

[smithy1]

Hi Andy,
You may well be right....also tried the A/B on acceleration trick with only the occasional pop or fart. Methinks John's CC is too good and all the firey stuff is way up in the primary/secondary zone. Too bloody efficient, that's the problem....that's my story anyway..

Will be fitting a second Bosch 044 pump to drive the hot streak independent of the A/B flow and have it entering into the primary zone to see if this help things. The 044 pumps have a check valve in their stock outlet fitting, so I will try to retain this if possible, if not I'll fit a couple of check valves in the lines. All part of the fun of doing our best to get these things to work. We'll get there eventually, just takes time and a little elbow grease.

Cheers,
Smithy.

[smithy1]

John,
Here's a couple of pics for you, let me know if you would like to see another view of it before I plonk it all back together again:


Just prior to start on Sunday afternoon.

Yesterday afternoon when I unloaded the "Beast" from my van and popped the top off to inspect the CC, clean as a whistle.

Obviously after removal of the CC, nothing untoward to see, some nice colour but no heat distress etc...

Looking into the turbine inlet, nothing untoward here either..! Beautiful work from John here. The P2 pressure gauge sense port can be seen in the 2 o'clock position inside the outer casing.


I "may" be taking the "Beast" to another  local car show this coming weekend if I can get all my ducks in a row..

Cheers,
Smithy.

[racket]

Hi Smithy

Thanks for the pics ............mmmmmm, Heh Heh , bit boring ;-) ........after my 10/98 flametube's first run jetandturbineowners.proboards.com/attachment/download/25 .

Yep, nice colours from radiant heat in the main body, pretty obvious line where the tertiary dilution occurs , it looks like the lower end of the "funnel" is still "silvery" stainless, temps down from plenty of mixing , LOL..... just an ordinary "no hassles" flametube.

Thanks again , always nice to see inside and check on how things have been working ...........I can file it away in the memory bank for later reference :-)

Cheers
John

[smithy1]

Hi John,
Yeah, she's nice and clean inside and nothing like your 10/98's first run, (I remember you sending that pic to me many moons ago)....and it's obvious there's plenty of tertiary dilution happening, I suspect this may be the issue with the hot streak not working, I had it entering into one of the large tertiary holes with the nozzle outlet a good 1" below that, needless to say there's not much in the way of flames way down there.

I'll set about fitting my hot streak nozzle outlet a lot further up the flame tube. There's not a lot of room between the outer case and the upper part of the flame tube, so I might fit my connector in the bottom half of the outer case which will give me plenty of room to fit internal fittings and stainless tube, which I'll run up the outside of the flame tube, I think I'll go -3 this time, that's still plenty for a hot streak.

I'll take some more pics as I go so you can see what I've done.

Cheers,
Smithy.

[racket]

Hi Smithy

I just noticed in an earlier email from Andrew that you guys discussed the possibility of the P2 pressure being higher than the A/B fuel pressure , thats a possibility, heres my reasoning ..............the A/B fuel ring has 16 X 1mm holes , with the pump only supplying ~3.4 lpm thats only a tad over 200 ml/hole , now back when I was making the 2 shaft kart I did some testing of flows thru its 4 hole fuel distributor , it had 4 X 1/32"( 0.8mm) holes and flowed at ~200ml/hole/min at 5psi fuel pressure .

If the GT6041 had 5 psi in the combustor there might not have been sufficient pressure available to get the hot streak to work .

Cheers
John

[smithy1]

Aug 26, 2014 4:55:10 GMT -5 racket said:

Hi Smithy

I just noticed in an earlier email from Andrew that you guys discussed the possibility of the P2 pressure being higher than the A/B fuel pressure , thats a possibility, heres my reasoning ..............the A/B fuel ring has 16 X 1mm holes , with the pump only supplying ~3.4 lpm thats only a tad over 200 ml/hole , now back when I was making the 2 shaft kart I did some testing of flows thru its 4 hole fuel distributor , it had 4 X 1/32"( 0.8mm) holes and flowed at ~200ml/hole/min at 5psi fuel pressure .

If the GT6041 had 5 psi in the combustor there might not have been sufficient pressure available to get the hot streak to work .

Cheers
John

That does sound feasible, Andrew (enginewhisperer), AndyM and yourself are probably correct, I should have thought this through a bit more perhaps .

I think the best course of action is to run the two 044 pumps in parallel for the A/B flow via a decent check valve, that should be plenty ....then a smaller separate high pressure pump, (independent of the other two), for the hot streak running through the solenoid and it's own check valve via another feed line, this should eliminate any possibility of P2 pressure causing grief ....does that sound like a plan??

We'll get it sorted eventually. 

Cheers,
Smithy.

[racket]

Hi Smithy

Yep , an independent pump sounds good , that way you can also test the hot streak without needing the A/B fuel pumps going , .........you might also be able to get the A/B to light at higher P2s as well, the dedicated pump will adjust to whatever the P2 is .

You'll have it sorted in no time :-)

Cheers
John

[smithy1]

Aug 26, 2014 16:59:10 GMT -5 racket said:

Hi Smithy

Yep , an independent pump sounds good , that way you can also test the hot streak without needing the A/B fuel pumps going , .........you might also be able to get the A/B to light at higher P2s as well, the dedicated pump will adjust to whatever the P2 is .

You'll have it sorted in no time :-)

Cheers
John

I do have a smaller high pressure pump sitting at home which may do the job, it's ~1/2 the volume capacity of the 044 pump but can still deliver a decent pressure, up to ~4bar, so that may well do the trick for us. I've made a new fitting for the lower outer combustion case to suit the hot streak, just need to bend up a new internal stainless line and point it in the appropriate direction and I should be good to go for further testing.

Has been raining pretty heavily here in Sydney over the last few days, actually raining quite hard as I type.... hopefully it'll clear up soon so I can do a little more work/testing on the "Beast".

Cheers,
Smithy.

[racket]

Sounds good :-)

[smithy1]

Hi John,

Here's a pic of the hot streak internal line, just mocked up at the moment... obviously I've not bent it neatly into place or lockwired it to the flame tube, I was just getting lengths and positions correct before final fitting. Where it goes into the primary zone, I have it bent to point directly at the turbine housing inlet via a 1mm orifice.

I have started fitting the second Bosch 044 pump and it's plumbing behind the drivers seat, still need to pick up a couple of fittings and some spare fuel hose hopefully this afternoon.... should be done by tomorrow-ish. I'll then set about getting the switch, fuse and relay wiring sorted, shouldn't take too long..I hope!



Cheers,
Smithy.

[racket]

Hi Smithy

If it doesn't catch fire in there , it never will :-)

It must be getting a bit "crowded" behind the seat with all these extra bits and pieces , LOL....you'll be needing universal jointed elbows to work in there.

Cheers
John

[smithy1]

Aug 27, 2014 17:44:30 GMT -5 racket said:

Hi Smithy

If it doesn't catch fire in there , it never will :-)

It must be getting a bit "crowded" behind the seat with all these extra bits and pieces , LOL....you'll be needing universal jointed elbows to work in there.

Cheers
John

Well, to be honest, it should look ok, I've got a nice "twin" pump bracket to hold the 044 pumps....the plumbing should be relatively functional if not terribly neat.... with a separate third pump to come in the near future. This A/B system is going to have some serious fuel flow potential. I'll be testing the system with one 044 pump for the A/B and the other supplying the hot streak....As you mentioned....if it doesn't light now there's something seriously wrong..!! The second 044 will be transferred to the A/B system when I get the third pump online, this third one will then feed the hot streak....Plenty more testing to be done...I'm more than happy with the running and performance of the engine itself...it's just all the ancillary bit's 'n bob's which can cause some grief and unanticipated issues.  

I've got the right side of the kart up on a piece of timber ~8" off the ground so I can get at the bolts etc from underneath.....and have temporarily removed the seat so I can actually get in there to work on things....much more betterer...

Cheers,
Smithy.

[racket]

Hi Smithy

I've seen inside the 1/4 scaler and your a magician at fitting lotsa bits into a small space in an orderly way , the kart will undoubtedly be up to the same standard by the time you're finished with her .................yep, some serious flow rates with all those pumps onboard , LOL...... you'll hear the whistle of air going into the fueltank over the sound of the afterburner ;-)

Heh heh , when I was making the kart I had her up on a couple of builders saw horses to save my back , karts are buggers to work on , I even contemplated fitting a chain block off the shed rafters so I could hoist her up wherever I needed to work on her, that GT6041 is one heavyweight lump of a turbo to lift around.

Cheers
John

[smithy1]

Yeah...I think you're right about the air going into the fuel tank....I better make sure there's plenty of "breather" available....I'd hate to see the tank trying to suck itself inside-out...or should I say "atmospheric pressure" trying to push it in...

I have a chain block in the shed....strangely...I never even thought of using it.... I also have a couple of those load straps used for towing 4WD's out of trouble, they should do the trick nicely.

What do you think she'd weigh John..?? I'm guessing ~200kgs or so???

Cheers,
Smithy.